Field of the Invention
The present disclosure relates to a technical field of preparing a titanium metal by molten salt electrolysis, more particularly, to a method for directly producing a titanium metal powder with titanium-containing material such as high titanium slag and rutile.
Background Art
A titanium metal has many advantages such as low density, good corrosion resistance, plasticity, high specific strength and the like, which is widely used in fields such as aerospace, artificial satellite, military industry, chemical industry, petroleum, metallurgy, light industry, electric power, seawater desalination, naval ships, textile process and medical treatment, thus the titanium metal is acclaimed as the Metal of 21st.
Currently, the industrial production method of sponge titanium is still a magnesiothermic reduction process, which includes: a titanium mineral is enriched, chlorinated and rectified to prepare TiCl4, then after the TiCl4 is reduced to the sponge titanium using magnesium in argon or helium inert atmosphere, the magnesium and MgCl2 are separated and removed by performing vacuum distillation, finally the sponge titanium is finishing processed to obtain a finished sponge titanium. The method has a high productivity and facilitates commercialization, thus it seems that this method is irreplaceable so far. However, the method has disadvantages such as long process flow, long production period, low reduction ratio, high price of a reducing agent, and difficulty in achievement of continuous processes, resulting in high manufacturing cost of the sponge titanium.
There are many methods for preparing a titanium metal, and representative methods are as follows: an FFC method proposed by Cambridge University, an OS method proposed by Kyoto University, a PRP method proposed by Okabe etc. from Japan, and fluotitanate reduction etc. However, the industrialization has not been realized so far, because each method has technical problems that cannot be resolved currently.
A Chinese patent application with a publication number CN1712571 A discloses a method of preparing pure Ti through electrolysis directly from solid solution anode TiO.mTiC with metal conductivity. The solid solution anode TiO.mTiC in this method uses carbon and titanium dioxide or titanium carbide and titanium dioxide as raw material, the raw material is mixed in powder form based on reaction stoichiometry, then the raw material is pressed and molded and the raw material reacts in vacuum at 600-1600° C. to obtain the solid solution anode TiO.mTiC. The above method has the advantages such as simple process, and continuous electrolysis processes; however, the method needs to prepare solid solution TiO.mTiC under the conditions of vacuum and high temperature, thus the method has a high energy consumption and uses high-cost titanium dioxide as materials.
An United States patent document with a publication number U.S. Pat. No. 7,410,562B2 discloses a method of preparing a titanium metal using a composite anode of TiO2—C, which is a combination method of a thermal and an electrochemical process, and the key point of which is heating carbon and titanium-containing material to form a TiCxOy composite anode, then using the TiCxOy composite anode as a soluble anode to perform molten salt electrolysis, and obtaining the titanium metal at a cathode. The method has the similar advantages and disadvantages to those in the above Chinese patent application, that is, the method also needs to prepare composite anode by thermal reduction under the conditions of vacuum and high temperature, thus the method also has high energy consumption, and which also uses high-cost titanium dioxide as materials.